Electromagnetic switch assembly

ABSTRACT

An electromagnetic switch for monitoring the current-carrying capability of a load device such as a headlamp and energizing an alarm device in the event the load device fails to conduct current. The switch comprises a magnetic core and a winding connected serially between the load device and a source. A pivotal armature is biased away from the core to close a circuit from the source through the core and the armature to the alarm device when the winding is deenergized. A double switch assembly operating a single alarm is also disclosed.

United States Patent [72] Inventor William B. Kindred 14659 Horger, Allen Park, Mich. 48101 [2]] Appl. No. 864,582 [22] Filed Oct. 8, 1969 [45] Patented June 15, 1971 [54] ELECTROMAGNETIC SWITCH ASSEMBLY 16 Claims, 7 Drawing Figs.

[52] US. Cl..... 335/ 107 [5 l] Int. Cl. H0lh 67/00 [50] Field Search 335/107, 106, 19, 146, 187, 192. 194; 340/251; 317/157 [56] References Cited UNlTED STATES PATENTS 2,440,265 4/1948 Gross 335/ M6 2.674 730 4/1954 Klebanoff Primary Examiner -l-larold Broome Attorney-Barnard, McGlynn and Reising ABSTRACT: An electromagnetic switch for monitoring the current-carrying capability of a load device such as a headlamp and energizing an alarm device in the event the load device fails to conduct current. The switch comprises a magnetic coreand a winding connected serially between the load device and a source. A pivotal armature is biased away from the core to close a circuit from the source through the core and the armature to the alarm device when the winding is deenergized. A double switch assembly operating a single alarm is also disclosed.

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ATTORN ZVJY/ZZZH? Kindred I I B v ELECTROMAGNETIC SWITCH ASSEMBLY broken and thereafter be incapable of carrying a current. For

various reasons the operator may not become immediately aware of such a failure unless he is positively advised of such failure. 4 r

In accordance with the present invention, the operability of an electrical load device, such an automobile lamp or com- I bination of such lamps, may be continuously monitored during the period of intended operation thereof by monitoring the current-carrying capability of such load device and providing a positive indication of the failure of such device to properly pass current. In general, this is accomplished by means of an electromagnetic switch assembly comprising a conductive, magnetic core having spaced poles, a winding disposed thereon mediate the poles, and conductive means for electrically connecting the winding between the source of potential and a load device. In addition, the assembly comprises a contact which is disposed adjacent the poles and which is adapted for electrical connection to an indicator device such as a small signal lamp. A spring-biased armature cooperates with the core and the contact such that the passage of current through the winding maintains the armature out of engagement with the contact. The failure of the load device and consequent interruption of current through the winding, permits the annature to engage the contact thereby to connect a source of potential to the indicator device through the core, armature, and contact.

In one specific embodiment of the invention, a double electromagnetic switch assembly is adapted for direct connection to a double filament headlamp to provide a warning if either of the filaments fails to carry current during its period of intended use. In this embodiment, two magnetic cores are mounted in a single assembly to operate respective springbiased armatures relative to a centrally disposed common contact so that either armature can excite the contact.

In another specific embodiment, the subject switch assembly may be disposed between the terminals of a headlight and the wiring harness of an automobile. This embodiment employs input connectors adapted to receive the headlamp terminals and output connectors adapted for connection to a wiring harness so that the assembly may be installed on an after-market" basis.

Further features and advantages of the invention will be made more apparent in the following specification which is to be taken with the accompanying drawings in which:

FIG. I is a schematic view partly in cross section of an illustrative embodiment of the invention in a first condition,

FIG. 2 shows the embodiment of FIG. 1 in a second condition;

FIG. 3 is a sectional view of the components of a second illustrative embodiment of the invention;

FIG. 4 is an assembly view in perspective of the components of the embodiment of FIG. 3 with the cover removed;

FIG. 5 is an exploded view of certain components of the FIG. 4 embodiment;

FIG. 6 is an assembly view in perspective of a third illustrative' embodiment; and,

FIG. 7 is an exploded view of certain components of the FIG. 6 embodiment.

Referring now to FIG. I, there is shown an electromagnetic switch assembly I0 for monitoring the operability of an electrical load device 12 which may be an automobile headlamp or taillamp having a filament 1 4. The load device 12 is normally provided with ,current from a source 16 which may represent the ordinary automobile battery, through selective operation of the usual instrument panel switch 18. The electromagnetic switch assembly 10 monitors the current-carrying capability of the load device 12 and upon failure of such load device to carry an electrical current-causes energization of an indicator device 20 which may be a small, incandescent lamp disposed within an automobile and within the field of view of the operator.

The electromagnetic switch assembly 10 comprises a hollow, insulative housing 22 which carries therein a conductive and magnetic U-shaped core 24 having spaced coplanar pole surfaces 26 and 28. An electromagnetic winding 30 having a plurality of turns is disposed on the core 24 mediate the pole surfaces 26 and 28. One end of the winding 30 is electrically connected to the core 24, as shown, and the other end of the winding is electrically connected to a female-type electrical connector 32 which extends through a first opening in the housing 22. Connector 32 is adapted to receive a male connector 34 which normally carries current to the filament 14 of the load device 12. Electrically connected to the core 24 is a male-type connector 36 which extends through a second opening in the housing 22 so as to be received in and by a second female connector 38 which is electrically connected in series with the source 16 through the load operating switch 18. The connector 36 may be suitably welded, soldered, or brazed to the core 24 to'establish a rigid mechanical connection as well as a permanent electrical connection. Accordingly, when the load device 12 is operative, current is directed from the source 16 through the switch 18, the connectors 38 and 36, the core 24, the winding 30, the connectors 32 and 34 to the filament 14.

A conductive, magnetic armature bar 40 of flat rectangular shape is disposed within the housing 22 and has one end pivotally engaging the pole surface 28 of the core 24. The other end of the armature bar 40 extends toward the other pole surface 26 but is displaceable relative thereto in accordance with the opposing influences of the electromagnetic attraction of the core 24 and the mechanical bias of an arcuate nonmagnetic but conductive spring 42. Spring 42 which may be made of beryllium copper, has one end thereof secured by spot welding to the armature bar 40 at a point between the ends thereof and the other end in engagement with the pole surface 26. The arcuate profile shown in FIG. 1 represents the normal geometry of spring 42 which displaces the left-hand end of armature 40 as shown in FIG. 1 upwardly and away from the pole surface 26. Spring 42 is compressed into a substantially fiat condition by displacement of the armature bar 40 toward the pole face 26 as will subsequently be described with reference to FIG. 2. 7

Housing 22 also carries an integral contact-connector 44 the contact portion 45 of which is disposed within the interior of the housing and protrudes toward the upper surface of the armature bar 40 as shown in FIG. I. The connector portion of contact-connector 44 is a female-type electrical connector which extends through a third opening in the housing 22 and which is adapted to receive a male-type connector 46 electrically connected in series with the indicator device 20. Accordingly, when the armature bar 40 is in the position shown in FIG. 1, i.e. in contact with the contact-connector 44, an electrical circuit is established between the source 16 and the indicator device 20 through the switch 18, the connectors 38 and 36, the core 24, the armature bar 40, the contact-connector 44, and the connector 46. Current may also flow through spring 42. Accordingly, FIG. 1 represents the condition of the electromagnetic switch assembly 10 when the switch 18 is open circuited such that source16 is supplying no current to either the load device 12 or the indicator device 20. It also represents the condition of the assembly 10 when switch 18 is closed but the filament 14 of the load device 12 is broken such that no current passes through the winding30 to maintain the armature bar 40 out of contact with the contact-connector 44.

Accordingly, with switch 18 in the closed circuit condition, current passes from the source 16 to energize the indicator lamp 20, thus, advising an operator that electrical current is being supplied to the load device 12, but that the device itself is not passing electrical current. I

. FIG. 2 represents the condition of the electromagnetic switch assembly when the load device 12 is properly passing electrical current. Under this condition, current passes from the source 16 of FIG. 1 through the connector 36 and the core 30 to the load device 12. Current through the winding 30 produces magnetic flux in the core 24 which flux produces a force of attraction on the displaceable end of the armature bar 40 tending to bring the armature bar 40 into such a position as to minimize the air gap in the magnetic circuit which includes core 24. Displacing the armature bar 40 to the position shown in FIG. 2 loads and flattens the nonmagnetic spring 42 and also takes the armature 40 out of electrical contact with the contact-connector 44. Accordingly, in the condition represented by FIG. 2, no electrical connection exists between the connector 36 and the contact-connector 44. Therefore, the indicator device is not connected to the source 16 as shown in FIG. 1 because the load device 12 is properly passing current.

In the compressed and flattened condition shown in FIG. 2, a portion of the nonmagnetic spring 42 resides between the displaceable end of the armature bar 40 and the pole surface 26 of the core 24. With the spring 42 in this interposed position, the possibility of a sticking effect due to residual magnetism in the core 24 will be eliminated and the armature 40 will immediately release upon interruption of current through the winding 30 and will be displaced toward the contact connector 44 to establish electrical connection to the indicator device 20.

Looking now to FIGS. 4 and 5, a double electromagnetic switch assembly 50 is shown for monitoring the operability of the two filaments of a sealed beam double filament headlamp as represented by the high beam terminal 52 and the low beam terminal 54. Assembly 50 provides an output signal to a warning device via output line 60 should one or the other of the two filaments fail during the intended operation thereof. High and low-beam filament terminals 52 and 54 have separate input supply lines 56 and 58, respectively, which form part of an input wiring harness for the headlamp. Assembly 50 comprises a first U-shaped conductive core 62 having coplanar spaced pole surfaces .64 and 66 and carrying an; electromagnetic winding 68. One end of winding 68 is electrically connected to a female headlamp terminal connector 70 and the other end of the'winding is electrically connected to the core 62. Core 62 is in electrical contact with a combined support and input connector member 72 which, as best shown in FIG. 5, includes spaced upstanding fingers 76 and 78 which resiliently engage the opposite legs of the core 62 to hold it in position in the overall assembly. The female connector portion of member 72 is adapted to receive the input terminal connector 74 of the high beam supply line 56.

Core 62 together with winding 68 is adapted to control the position of a rectangular magnetic armature bar 80 which has a rectangular, 'arcuate, nonmagnetic spring 82 secured thereto. One end of the armature bar 80 isplaced in pivotal contact with the pole surface 66 and the other end of the armature is biased away from the pole surface 64 by the spring 82. With the core 68 energized, the spring 82 flattens to minimize the air gap between the armature bar 80 and the pole surface 64 in a manner similar to that described with reference to FIG. 2. When the core 62 receives electrical current from supply line 56 but this current is not conducted by the filament represented by terminal 52, no current passes through the winding 68 and, accordingly, the armature bar 80 is biased by spring 82 into engagement with a first contact 84 of a two-way contact and connector member 86 which is disposed centrally within the assembly 50. As best shown in FIG. 5, member 86 includes a lower female-type connector portion 88 which is adapted for electrical connection to the connector 90 on the end of the warning signal line 60. Member 86 also includes an upper portion having oppositely extending pointed contacts 84 and 92 of which contact 84, as previously described, is operated by the armature bar 80.

Assembly 50 comprises a second magnetic conductive core 94 carrying a winding 96 between coplanar spaced pole surfaces 98 and 100. One end of the winding 96 is connected to a female-type contact 102 which is adapted to receive the lowbeam filament terminal 54. Accordingly, contact 102 is disposed at right angles to the high-beam contact 70 whereas the cores 62 and 94 face one another as shown in FIGS. 3 and 4. The other end of winding 96 is electrically connected to the core 94. The core 94 is in turn in electrical contact with the resilient fingers 104 and 106 of a combined support and connector member 108, as shown in FIG. 5. Again the opposite legs of the core 94 are disposed between the fingers 104 and 106 to be held in position thereby and also to make the necessary contact. Member 108 is adapted tobe connected to the low beam input line via a male connector 110. Core 94 and winding 96 control the location and displacement of a second armature bar 112 which is disposed within the assembly 50 in permanent contact with pole surface 98 but biased away from the pole surface by the rectangular, arcuate, nonmagnetic spring 114 which is spot welded to the armature bar 112 in the same manner the spring 82 is spot welded to the armature bar 80. When no current is passed by the winding 96, the spring 114 urges the end of the armature bar 112 into engagement with the pointed contact 92 of the member 86.

Accordingly, with either of the supply lines 56 and 58 energized, a failure of the filament connected to that supply line to pass current results in the engagement of one of the armature bars 80 and 112 with one of the contacts 84 and 92 of the member 86. Upon such engagement, a circuit is completed to the output line 60 through the member 88 to energize an alarm device in accordance with the principles of operation described with reference to FIGS. 1. and 2.

Finally, it is noted that the headlamp ground terminal 116 is adapted to be received by a ground connector 118 which in turn is connected to a ground line 120. i

The assembly 50 of FIGS. 4 and 5 is shown in section in FIG. 3. In FIG. 3 the assembly 50 is shown placed into an insulative housing 122 having a hollow interior with partly defined side compartments for the connectors 70 and 118 and a fully enclosed side compartment for the connector 102. The central member 86 having the oppositely facing contacts 84 and 92 is shown disposed in the center of the central compartment and having the large planar center section wedged within appropriately dimensioned and located slots in the opposite walls of the housing.

The embodiment of FIGS. 3, 4, and 5 is particularly adapted for permanent installation into an automobile wiring harness. On the other hand, the embodiment of FIGS. 6 and 7 is particularly adapted for after-market installation and is, therefore, adapted to be disposed between the ordinary headlamp and the wiring harness normally associated with that headlamp. In FIG. 6 and 7, female-type high and low beam filament connectors 126 and 128 are provided along with a ground connector 130 each having a male terminal blade adapted for connection into the wiring harness in place of the normal terminal blades of the headlamp. High-beam terminal connector 126 is electrically connected to one side of a winding 134 which is disposed on a first core 136. Core 136 has coplanar spaced pole surfaces 138 and 140 which are adapted to be engaged by the spaced, resilient fingers 142 and 146 of a nonmagnetic spring member mounted on the inside face of a combined contact and terminal member 146 having a maletype high-beam terminal blade 148 which is adapted to fit into the headlamp wiring harness in place of the regular high beam filament terminal 52 shown in FIG. 4. Accordingly, when current is applied to the blade 148 and transducer filament connected to connector 126 is operative, an electrical circuit is completed through the blade 148, member 146, spring fingers I42 and 144, core 136, winding 134, and the connector 126.

However, when the filament'to which connector 146 is connected fails to pass the current, the winding 134 is no longer energized. Under these conditions an armature bar 150 is urged away from the pole surface 138 of the core 136 by an arcuate rectangular spring 152 which is, for all practical purposes, identical to the spring 82 of the assembly 50 of FIG. 4. When the armature bar 150 is urged away from the pole surface 138, it engages the contact 154 of a combined contact and connector member 156 as shown in FIG. 7. Member 156 has a rolled lower portion 158 which defines a female contact adapted to receive the male contact connected to a signal line 160 which is electrically connected to a warning device of the type shown in FIG. 1. Accordingly, when the armature bar 150 is disposed with one end in engagement with pole surface 140 of the core 136 and the other end in engagement with the contact 154 of member 156, an electrical circuit is completed from the blade 148 through the springs 142 and 144, the core 136 and the armature bar 150, and the member 156 to the signal line 160 which is connected to a signal lamp of the type illustrated in FIG. 1. I

The apparatus of FIGS. 6 and 7, like the apparatus of FIGS. 4 and 5, is adapted to provide a single warning in response to the failure of one of two monitored loads. The one load as previously described is represented by the filament terminal 52. The other load is represented by the low-beam filament terminal 54 which 'isadapted to be received in the connector 128. Connector 128 is electrically connected to one end of a winding 162 mounted on a second core having coplanar spaced pole surfaces 164 and 166. The other end of winding 162 is connected to the core. The pole surfaces 164 and 166 are shown in FIG. 6 to be engaged by the resilient fingers 168 and 170 of a nonmagnetic spring member secured to the combined support and terminal member 172. Member 172 has a male-type-terminal blade 176 which is adapted to fit into the wiring harness in place of the low-beam filament terminal 54 and an intermediate section 174 which is adapted to interconnect the two perpendicular portions 172 and 176.

The energization of winding 162 controls the position of an armature bar 178 which has one end in engagement with the pole surface 164 and the other end spaced from the pole surface 166 by an arcuate, nonmagnetic spring 180. When the armature 162 is energized, the armature bar 178 is drawn as close as possible to the pole surface 166, the spring 180 being disposed between the pole surface and the armature bar. When the winding 162 is deenergized, the armature bar is urged by spring 180 into engagement with a second contact 182 of the member 156 which extends oppositely to contact 154. Accordingly, a failure of the low beam filament is also operative to complete an electrical circuit from the blade 176 through the fingers 168 and 170 to the core and the associated armature bar 178 and the contact 182 to the signal line 160.

It is to be understood that the foregoing embodiments are illustrative in nature and are not to be construed in a limiting sense.

The embodimentsof the invention in which an exclusive property or privilege is claimed are defined as follows:

Iclaim: j

l. A current sensing electromagnetic switch assembly for monitoring the opcrability of an electrical load device comprising: a housing, a conductive magnetic core disposed within the housing and having spaced poles, first conductor means electrically connected to the core for connection to a source of potential; a winding disposed on the core mediate the poles and having one end electrically connected to the core, second conductor means for connecting the other end of the winding to a load device; third conductor means for connection to an alarm device and having a contact portion within the housing; a magnetic conductive armature having one end in engagement with one pole and the other end displaceable between the other pole and the contact portion, and spring means for urging the armature toward the contact portion.

2. The assembly defined in claim l-wherein said spring means comprises a normally arcuate nonmagnetic member having one end secured to the armature and the other end engaging said other pole such that excitation ofsaid winding causes displacement of the armature toward said other pole thereby to straighten the arcuate spring means.

3. The electromagnetic switch assembly defined in claim 2 including an alarm device connected to the third conductor means and energized by current through the core, armature and third conductor means.

4. Apparatus as defined in claim 1 wherein the first conductor means comprises a rigid member having spaced resilient fingers engaging the legs of the core adjacent the poles and a connector portion extending from the fingers.

5. Apparatus as defined in claim 4 wherein the connector portion of the first conductor means is female.

6. Apparatus as defined in claim 1 wherein the second conductor means includes a female connector portion adapted to receive a headlamp filament terminal.

7. Apparatus as defined in claim 1 wherein the third conductor means includes a flat body portion having the contact portion at one end and a connector portion at the other end.

8. Apparatus as defined in claim 1 wherein the poles are coplanar, the armature being rectangular and disposed across the poles.

9. A switch assembly for double filament lamps comprising:

a housing, first and second conductive cores disposed within the housing and having spaced pole surfaces, first and second input conductor means electrically connected to the first and second cores, respectively, and adapted for connection to a source of potential, first and second windings on the first and second cores, respectively, each having an end electrically connected to the associated core, first and second output conductor means for connecting the other ends of the winding to respective lamp filaments, a warning signal conductor means for connection to an alarm device and having first and second contact portions, and first and second magnetic armature having one end in engagement with a pole surface of the first and second cores, respectively, and another end displaceable between the other pole surfaces and the first and second contact portions, respectively. 10. Apparatus as defined in claim 9 including first and second nonmagnetic spring means disposed between the first and second armatures and said other pole surfaces of the first and second cores, respectively, to bias the armatures into engagement with the respective contact portions.

11. Apparatus as defined in claim 9 wherein the input conductor means are female types.

12. Apparatus as defined in claim 9 wherein the input conductor means are male blade types arranged according to the arrangement of filament terminals on a double-filament headlamp.

13. Apparatus as defined in claim 9 wherein the input conductor means are rigid members having spaced resilient fingers engaging the legs of the respective cores adjacent the pole surfaces thereof.

14. Apparatus as defined in claim 8 wherein the corresponding pole surfaces of the first and second cores face one another.

15. Apparatus as defined in claim 14 wherein the warning conductor means includes a fiat body portion having said first and second contact portions oppositely extending from one end mediate the cores and a connector portion at the other end.

16. Apparatus as defined in claim 15 wherein one of the input conductor means includes a connector terminal portion opposite the resilient fingers and disposed in a plane intersecting the plane of the fingers at a right angle. 

1. A current sensing electromagnetic switch assembly for monitoring the operability of an electrical load device comprising: a housing, a conductive magnetic core disposed within the housing and having spaced poles, first conductor means electrically connected to the core for connection to a source of potential; a winding disposed on the core mediate the poles and having one end electrically connected to the core, second conductor means for connecting the other end of the winding to a load device; third conductor means for connection to an alarm device and having a contact portion within the housing; a magnetic conductive armature having one end in engagement with one pole and the other end displaceable between the other pole and the contact portion, and spring means for urging the armature toward the contact portion.
 2. The assembly defined in claim 1 wherein said spring means comprises a normally arcuate nonmagnetic member having one end secured to the armature and the other end engaging said other pole such that excitation of said winding causes displacement of the armature toward said other pole thereby to straighten the arcuate spring means.
 3. The electromagnetic switch assembly defined in claim 2 including an alarm device connected to the third conductor means and energized by current through the core, armature and third conductor means.
 4. Apparatus as defined in claim 1 wherein the first conductor means comprises a rigid member having spaced resilient fingers engaging the legs of the core adjacent the poles and a connector portion extending from the fingers.
 5. Apparatus as defined in claim 4 wherein the connector portion of the first conductor means is female.
 6. Apparatus as defined in claim 1 wherein the second conductor means includes a female connector portion adapted to receive a headlamp filament terminal.
 7. Apparatus as defined in claim 1 wherein the third conductor means includes a flat body portion having the contact portion at one end and a connector portion at the other end.
 8. Apparatus as defined in claim 1 wherein the poles are coplanar, the armature being rectangular and disposed across the poles.
 9. A switch assembly for double filament lamps comprising: a housing, first and second conductive cores disposed within the housing and having spaced pole surfaces, first and second input conductor means electrically connected to the first and second cores, respectively, and adapted for connection to a source of potential, first and second windings on the first and second cores, respectively, each having an end electrically connected to the associated core, first and second output conductor means for connecting the other ends of the winding to respective lamp filaments, a warning signal conductor means for connection to an alarm device and having first and second contact portions, and first and second magnetic armature having one end in engagement with a pole surface of the first and second cores, respectively, and another end displaceable between the other pole surfaces and the first and second contAct portions, respectively.
 10. Apparatus as defined in claim 9 including first and second nonmagnetic spring means disposed between the first and second armatures and said other pole surfaces of the first and second cores, respectively, to bias the armatures into engagement with the respective contact portions.
 11. Apparatus as defined in claim 9 wherein the input conductor means are female types.
 12. Apparatus as defined in claim 9 wherein the input conductor means are male blade types arranged according to the arrangement of filament terminals on a double-filament headlamp.
 13. Apparatus as defined in claim 9 wherein the input conductor means are rigid members having spaced resilient fingers engaging the legs of the respective cores adjacent the pole surfaces thereof.
 14. Apparatus as defined in claim 8 wherein the corresponding pole surfaces of the first and second cores face one another.
 15. Apparatus as defined in claim 14 wherein the warning conductor means includes a flat body portion having said first and second contact portions oppositely extending from one end mediate the cores and a connector portion at the other end.
 16. Apparatus as defined in claim 15 wherein one of the input conductor means includes a connector terminal portion opposite the resilient fingers and disposed in a plane intersecting the plane of the fingers at a right angle. 